(In reply to Stefan Gohmann from comment #2)
> We will use pysupport for the UCS 4 packages. The main problem is that we
> have to migrate the whole univention namespace at once.
No, you don't have to: <https://docs.python.org/2.7/library/pkgutil.html#pkgutil.extend_path> works quiet well.
The main problem by now is that lots of UCS packages hard-code files in /usr/share/pyshared/, which is wrong and will break left and right if we do the transition.
> I don't think it is the best solution to do it in such a big update.
And you propose to do it when instead? This is going to be an API change, so if not for a major release, when else?
We already procrastinated the change with Debian-Wheezy for UCS-4.0, and it gets worse with Debian-Jessie with UCS-4.2

(In reply to Philipp Hahn from comment #3)
> > I don't think it is the best solution to do it in such a big update.
>
> And you propose to do it when instead? This is going to be an API change, so
> if not for a major release, when else?
> We already procrastinated the change with Debian-Wheezy for UCS-4.0, and it
> gets worse with Debian-Jessie with UCS-4.2
And this will probably also ease the transition to Python 3, which is available in UCS 4.2 / Debian Jessie. In UCS 5.x the update will probably not break as much with dh_python than py_support.